Sometimes national weather stations, based on distance to your house or micro-climates, won't have the most accurate data.
I have actually warmed up to PWS stations. That's what I used last summer and was really pleased with the results.
You can actually verify the accuracy/data on a lot of the PWS stations out there. On the map screen you will see a 'More Info' link
Tap on that, and a lot of times you can see standard deviation for the data, how long it has been transmitting, etc.
This year we will have the ability to get observed precipitation with a ridiculous amount of resolution. No promises on dates, but that is the great thing about purchasing a cloud based controller, we will be able to continue to enhance with features no one has even imagined yet
Hope this helps.